OpenLayers Gallery

Carolinas RCOOS

The Project: The over-arching objective of this project is to integrate and enhance existing assets and observations in the NC and SC coastal region to create an end-to-end prototype regional coastal ocean observing system (RCOOS). The Tech: Mapserver is running as our mapserving engine, with OpenLayers being the client side of course. A couple of notable things we've done on this that others may find useful is the use of a SQLite database to replace shapefiles for the GetFeatureInfo requests for our real time data points. This gives us the ability to style the data in an HTML table then display it in our info area without having the cost of styling it real time. Our GetFeatureInfo database is updated once an hour. The reason behind the use of SQLite is the fact taht the text field in a shapefile limited us to 255 characters. We use SQlite for our data storage as well, so we thought it would be an interesting endeavor to get the OGR SQLIte connection up and running to see if we could do it. I'm also using TileCache to try and give us the best of both worlds(meaning the response of static images with the flexibility of dynamic data generation). I've TileCached our base map, as well as the data points. I have 2 layers for the data points, the TileCache layer which is visible and then an invisible layer to handle the GetFeatureInfo requests. Another project we are going to undertake is a TileCache flushing mechanism to flush the dynamic layers at their update interval. For instance, we have some radar layers that update N Times an hour. It would be nice to cache them to cut down on the source retrieval time through mapserver, however to keep them current we'll have to flush them and re-cache them on a set interval. The layerswitcher is a custom tree that I developed using an example I found on Nabble. It is fairly basic, but accomplishes the goal of keeping the map itself free from obstructions. I'd be happy to answer any questions about what we've done or how we do it. Just email me at dan at inlet dot geol dot sc dot edu.